* {
  box-sizing: border-box;
}

body {
  padding: 0;
  margin: 0;
  font-family: Arial, Helvetica, sans-serif;
  background-color: #4682b4;
  display: flex;
  height: 100vh;
  align-items: center;
  justify-content: center;
}

.item {
  width: 150px;
  height: 150px;
  background-color: white;
  border: 3px solid black;
  position: absolute;
  z-index: 2;
}

.box {
  width: 150px;
  height: 150px;
  background-color: white;
  border: 3px solid black;
  position: absolute;
  z-index: -1;
}

.what {
  width: 150px;
  height: 150px;
  background-color: white;
  border: 3px solid black;
  position: absolute;
}
